The present invention relates to a process for the preparation of polycarbonates and to compositions based on such polycarbonates.
The preparation of polycarbonates, which compounds are herein defined as polymeric reaction products of carbon dioxide and an epoxy compound is known.
U.S. Pat. No. 4,500,704 discloses a process for the preparation of linear polycarbonates which process employs a double metal cyanide complex as the catalyst. Said process is preferably carried out at a pressure in the range of from 27.6 to 75.8 bar absolute. Below a pressure of 27.6 bar absolute, the product yields are low. Moreover, the process requires relatively long reaction times, as may be concluded from the examples where the shortest reaction time is approximately 48 hours.
U.S. Pat. No. 3,248,415 describes the preparation of polycarbonates in the presence of a potassium carbonate catalyst and an organic compound having at least 2 usually 2 to 4 active hydrogens. All examples, however, are restricted to the use of dihydric organic compounds. The process requires relatively high pressures, temperatures and long reaction times, while the resulting polycarbonates have a relatively low molecular weight.